Speciality Vessels:

Speciality vessels are constructed and used for specific purposes.
Tugs: A tug (tugboat) is a boat or ship that manoeuvres vessels by pushing or towing them
Tenders : A boat or a larger ship used to service or support other boats or ships, generally to transport people and/or supplies, is called a tender vessel.
Research Vessels : They are special types of vessels used to carry out a variety of research at sea. Some of the most common types of research vessels are – seismic vessels, hydrographic vessels, oceanographic vessels, polar vessels etc.
Salvage Vessels: Salvage vessels are vessels engaged in salvage operation; recovery of lost property at sea.
Barge Carriers : A barge is a flat-bottomed boat built mainly for river and canal transport of heavy goods.
Timber Carriers : Vessels that carry timber
Livestock Carriers : Vessels that carry livestock/animals